Fix request method of a few services

A few services are not limited to post requests only. Fix such that they
are.
Upgrade spray from v 1.1-M7 to 1.1-M8

Different server start in Boot.scala. Different Authorization header
parser in NilewappTokenAuthenticator.scala.
Change services to not extend HttpService

Import the Directives instead.
Update spray from v 1.1-M8 to 1.1-20131004

AuthenticationFailedRejections give causes for failed authentication not
just giving the realm. If no appropriate authoriztion header is present
for NilewappTokenAuthenticator it will indicate missing credentials and
if there are invalid credentials it will indicate rejected credentials.
SimpleTokenAuthenticator will always indicate rejected credentials.
Change STA to return CredentialsMissing

Change SimpleTokenAuthenticator to cause an
AuthenticationFailedRejection with CredentialsMissing as cause if the
token field isn't present.
Add GroupServiceSpec stub
Change depracated entityAs to responseAs

Method entityAs is deprecated in spary v 1.1-20131004 and is replaced
with method responseAs.